The present invention relates to a lancing apparatus for producing a puncture wound, in particular for obtaining a blood sample, which is to be analyzed for medical purposes. It comprises a magazine holder for a lancet magazine with a plurality of lancets, a lancet drive with a drive spring, a tensioning device for tensioning the drive spring, and a push rod, the push rod being adapted for coupling to a lancet located in the lancet magazine and the push rod being adapted for moving at high velocity, together with a lancet coupled thereto by means of the lancet drive during a puncture and retraction movement for producing a puncture wound. The apparatus also includes a magazine advancing mechanism for advancing the lancet magazine in such a manner that the lancets stored therein can be coupled to the push rod one after the other. The present invention also relates to a blood sampling system comprising such a lancing apparatus and a lancet magazine adapted thereto and including a plurality of lancets.
For sampling a small quantity of blood from a body part (usually from a finger or earlobe) for analytic-diagnostic purposes, lancets are used, which are pierced into the corresponding body part for producing a puncture wound. Blood sampling systems have been available for some time, which comprise a lancing apparatus and associated lancets specially tailored for the particular lancing apparatus. A lancet drive for piercing the lancet mechanically into the skin is located in a housing of the lancing apparatus.
Lancet devices have to fulfill difficult and partially contradictory requirements for minimal pain, simple operation, compact structure, and cost-effective construction. Extensive development work has been performed to fulfill these requirements to the extent possible. One direction of the development efforts has gone toward offering the user more comfort. Simple and comfortable operation is important, in particular, for diabetics, who have to check their blood glucose level frequently to be able to keep it within specific limits by insulin injections. In this context, the usage comfort of the systems is of very high medical significance, because the regular self-checking (“home-monitoring”) of blood sugar significantly reduces the risk of grave long-term damage of diabetes mellitus (e.g., retinopathies, which may result in blindness), and any improvement in operating comfort increases the willingness of the patients to perform regular self checking.
One possibility for increasing the comfort and making the operation of a lancing apparatus easier comprises the use of lancet magazines containing a plurality of lancets and adapted to be inserted into a magazine holder of a lancing apparatus. Thereby, the insertion of individual lancets, which is difficult, in particular for sick or frail people whose manual dexterity is restricted, is no longer required.
A blood sampling system having a drum-shaped revolver magazine, which contains 10 lancets located on a ring, is described in DE 10022720 A1. After each puncture, the magazine is advanced automatically, i.e., the magazine of the lancing apparatus is transported into the next position with a fresh lancet. A revolver magazine having a plurality of lancets located on a ring is also used in the blood sampling system described in EP 1384438 A1, which corresponds to U.S. patent application Ser. No. 10/445,606, no statements being made about its advancing.
A blood sampling system equipped with a lancet magazine is also described in WO 01/00090 A1. The system comprises a mechanism for automatic step-by-step advancement of the magazine. It is considered advantageous that a fresh lancet is thus used automatically for each new puncture. This applies similarly to U.S. Pat. No. 6,228,100. It teaches different configurations, by which an unused lancet, which is next in line, is brought into the usage position after each triggering of the lancet drive. The reuse of used lancets is thus prevented.
WO 03/071940 A1 and U.S. Pat. No. 6,530,892 describe lancet systems and consider it favorable that in each case the lancet magazine is advanced between two puncture steps in such a manner that each time a fresh lancet is made available.
In spite of these substantial development efforts, up to this point, lancing apparatuses comprising lancet magazines have not established themselves on the market. Therefore, there is a need to provide a magazine lancing apparatus which is better accepted by users.